1. Field of the Invention
The present invention relates to Fibre Channel networks, and more particularly, to address translation in Fibre Channel switches.
2. Background of the Invention
Fibre Channel is a set of American National Standard Institute (ANSI) standards, which provide a serial transmission protocol for storage and network protocols such as HIPPI, SCSI, IP, ATM and others. Fibre Channel provides an input/output interface to meet the requirements of both channel and network users.
Fibre Channel supports three different topologies: point-to-point, arbitrated loop and Fibre Channel fabric. The point-to-point topology attaches two devices directly. The arbitrated loop topology attaches devices in a loop. The Fibre Channel fabric topology attaches host systems directly to a fabric, which are then connected to multiple devices. The Fibre Channel fabric topology allows several media types to be interconnected.
Fibre Channel fabric devices include a node port or “N_Port” that manages fabric connections. The N_port establishes a connection to a fabric element (e.g., a switch) having a fabric port or “F_port”.
A Fibre Channel switch is a multi-port device where each port manages a point-to-point connection between itself and its attached system. Each port can be attached to a server, peripheral, I/O subsystem, bridge, hub, router, or even another switch. A switch receives messages from one port and routes it to another port.
Fibre Channel switches use memory buffers to hold frames received and sent across a network. Associated with these buffers are credits, which are the number of frames that a buffer can hold per fabric port.
Fibre Channel standards are now being extended for use with expanded Fabrics and in storage virtualization. Storage virtualization defines virtual storage units for end-users and maps virtual storage units to actual physical storage locations.
Fibre Channel proposed standard, T11/04-5200v0, incorporated herein by reference in its entirety describes multiple Fabrics and how they should be interconnected. FIG. 1F shows a block diagram of a system having multiple fabrics. Fabrics A,B,C,D,E and F are individual Fabrics. Host I1 attached to Fabric A uses Fabric Routers 1, 2 3, or 4 to communicate with devices T2 and T3. A Fabric Router is a Fibre Channel device that allows Fibre Channel devices, via N_Ports, to be shared among multiple independent Fibre Channel fabrics.
Fibre Channel proposed standard T11/04-395V2, incorporated herein by reference in its entirety, describes how Virtual Fabrics operate.
Commercial Fibre Channel switches fail to provide a system and method that can support such expanded functionality of Fibre Channel switches and accommodate various addressing schemes that are required to enable a switch to function properly in inter-fabric and virtual fabric routing.
Therefore, there is a need for a method and system for efficiently performing address mapping for a Fibre Channel switch that may operate in different environments, for example, multiple fabrics, virtual fabrics and storage virtualization.